HC05BD7

HC05BD7 Microcontroller Technical Summary

Overview

The HC05BD7 is an 8-bit HCMOS microcontroller from the M68HC05 family, designed for cost-sensitive applications requiring robust control capabilities. This MCU integrates multiple peripherals including I/O ports, PWM modules, timers, and analog-to-digital converters, making it particularly suitable for multi-sync computer monitor control applications.

Key Features

Hardware Features

• HC05 CPU Core with 8-bit architecture
• HCMOS technology for low power consumption
• Available in 40-pin DIP and 42-pin SDIP packages
• Memory options:
  • 256B RAM (HC05BD2 variant)
  • 384B RAM (HC05BD7 variant)
  • 5.75KB-11.75KB user ROM
  • 11.5KB user EPROM (HC705BD7 variant)
• 26 bidirectional I/O lines (14 dedicated + 12 multiplexed)
• 16 x 8-bit PWM channels with open-drain outputs
• On-chip oscillator
• DDC12AB interface module
• Multi-function timer
• 6-bit ADC converter
• Sync processor for display applications

Software Features

• HC05 instruction set with 62 instructions
• 11 addressing modes
• Multiple interrupt handling capabilities
• Low-power modes (STOP and WAIT)
• Watchdog timer functionality

Applications

• Multi-sync computer monitor controllers
• Display control systems
• Industrial control systems
• Consumer electronics
• Embedded control applications

Signal Description

Power Pins

• VDD: Power supply (4.5V to 5.5V)
• VSS: Ground reference

Clock Pins

• EXTAL, XTAL: External crystal oscillator connections
• Crystal Oscillator: Supports external crystal or resonator

Control Pins

• RESET: Active-low reset input
• IRQ/VPP: External interrupt input/programming voltage

I/O Ports

• PA0-PA7: 8-bit bidirectional I/O port A
• PB0-PB5: 6-bit bidirectional I/O port B
• PC0-PC7: Multiplexed I/O port with PWM and ADC functions
• PD0-PD3: Multiplexed I/O port with I2C and sync functions

Special Function Pins

• PWM0-PWM7: Dedicated PWM output channels
• HSYNC, VSYNC: Horizontal and vertical sync inputs
• SDA, SCL: I2C interface pins

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VDD): -0.3V to +7.0V
• Input Voltage: -0.3V to VDD + 0.3V
• Operating Temperature: -40°C to +85°C
• Storage Temperature: -55°C to +150°C

DC Characteristics (VDD = 5V ±10%, TA = -40°C to +85°C)

• Input High Voltage: 0.7VDD min
• Input Low Voltage: 0.2VDD max
• Output High Voltage: VDD - 0.5V min
• Output Low Voltage: 0.4V max
• Power Supply Current: 10mA typical (4MHz operation)

Timing Characteristics

• Oscillator Frequency: 1MHz to 4.2MHz
• Instruction Cycle Time: 1μs at 4MHz
• Reset Pulse Width: 1.5μs min
• Interrupt Pulse Width: 2 cycles min

Package Information

40-Pin DIP Package (Case 711-03)

• Package Type: Dual In-line Package
• Pin Count: 40
• Body Dimensions: 52.32mm x 13.97mm
• Lead Pitch: 2.54mm

42-Pin SDIP Package (Case 858-01)

• Package Type: Shrink Dual In-line Package
• Pin Count: 42
• Body Dimensions: 42.8mm x 10.16mm
• Lead Pitch: 1.778mm

CPU Core Architecture

Registers

• Accumulator (A): 8-bit general purpose register
• Index Register (X): 8-bit index/offset register
• Stack Pointer (SP): 16-bit stack pointer
• Program Counter (PC): 16-bit program counter
• Condition Code Register (CCR):
  • Half Carry (H) flag
  • Interrupt Mask (I) flag
  • Negative (N) flag
  • Zero (Z) flag
  • Carry/Borrow (C) flag

Memory Organization

• ROM: 5.75KB-11.75KB user program memory
• EPROM: 11.5KB user memory (HC705BD7 variant)
• RAM: 256B-384B data memory
• Memory-mapped I/O registers

Interrupt System

• External interrupt (IRQ)
• VSYNC interrupt
• DDC12AB interrupt
• Multi-function timer interrupt
• Software interrupt (SWI)
• Reset interrupt sequence

Operating Modes

• User Mode: Normal program execution
• Self-Check Mode: Factory test mode
• Bootstrap Mode: Special programming mode
• Low Power Modes:
  • STOP mode: Minimum power consumption
  • WAIT mode: Reduced power with timer active

Peripheral Modules

Pulse Width Modulation (PWM)

• 16 x 8-bit PWM channels
• Programmable duty cycle
• Open-drain output options

DDC12AB Interface

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